Smprovement in safety-valves for steam-boilers



H. S. JE-WELL & F. STEELE.

Improvement in Safety/Valves for Steam-Boilers.

No. 129,138. rarterptedmlymJaz STATES PATENT OFFICE."

HERBERT S. JEWELL AND FERDINAND STEELE, OF BROOKLYN, NEW YORK.

sMPRovEMEN-r IN ysAFlz'rv-v/Irvss FOR sTEAM-BouERs.

Specification forming part of Letters Patent No. 129,138, dated July 16, 1872.

To all whom t may concern:

Beit known that we, HERBERT S. JEWELL and FERDINAND STEELE, of Brooklyn, in the county of Kings and State of New York', have invented an Improvement in Safety-Valves and Alarms; and the following is declared to be a correct description thereof.

In Letters Patent N o. 123,076 a valve is shown in which a portion of the weight is suspended when more than the maximum pressure has been exceeded, thereby preventing the engine working at its entire power, but not entirely crippling the same and rendering it inoperative, as in those cases where the safetyvalve is held open.

The present invention is a modication of the mechanism that can be employed for accomplishing the same result. 1n our present improvement a portion of the weight that resists the movement of the safety-valve is discharged or dropped away from the main weight, so asl to render that weight lighter and the maximum pressure less, but not to otherwise interfere with the action ofthe valve.

In the drawing, Figure lis a vertical section of said safety-valve, and Fig-2 is a sectional plan at the line x x.

The valve-seat a is at the end of a suitable tube or connection, b, to the boiler, and around this seat is a casing, c, with a removable cover and an alarm-whistle, d, which may also be inclosed in a perforated case; and the parts should be made so as to be secured by a bar, locked to its place by the inspector after the gauge has been set at the determined pressure. '.Lhe valve f is at the lower end of the compound weight g, which is constructed so that when the same is raised by the maximum pressure a portion of the weight will be dropped or discharged. I have shown the weight hollow, into which shot, mercury, or other suitable material is inserted, to furnish the required weight in proportion to the area of the valve and the pressure at which the valve is to open. By this construction the pari are easily adjusted to suit varying pressures. Near the lower end of the hollow weight g an opening, t', is shown, that is of a character to allow the shot or other contents to run out when open; but this opening ordinarily is closed. In some cases a fusible plug is employed, that will melt at the temperature of the steam resulting from the maximum pressure, so that the valve will ordinarily open and close when the pressure is above or below the lowest or normal pressure; but when a high or dangerous pressure is reached the fusible plug will be melted, and the whole or a portion of the contents of the weight g will be dropped or discharged, and there will be less resisting weight, and a sure indication be obtained that the highest pressure has been exceeded. The same effect is produced when a latch or a slide is employed to retain a portion of the weight and allow the same to drop or disengage when the full extent of motion is given to the parts in consequence of the high pressure of steam.

A cock or gate may be provided for withdrawing the shot, mercury, or other material that may run out of the hollow weight g and where a latch or gate is made use of the parts are to be constructed so that they can be reconnected or replaced when the cap of the case c is taken olf.

We claim as our invention- The safety-valve made with a compound weight sliding within a case and provided with means for allowing a portion of such weight to drop when the maximum pressure has been exceeded, substantially as and for-the purpose Set forth.

Signed by us this 11th day of March, A. D.

HERBERT S. JEWELL. f FERDINAND STEELE. Witnesses:

GEO. T. PINCKNEY, CRAs. H. SMITH. 

